I've got information Premiere Pro and After Effects requires at least ~800mb of video memory to be able to use CUDA acceleration. I'm going to buy Macbook Pro base line with GT 650m 512mb of vram. Big question - is this really enouth for cuda and all other features PR and AE has?

Well actually you are much better off spending that extra $400 because you not only get the 1 GB VRAM you also get 8 GB of regular RAM versus the other model and you get a faster CPU. This is money well spent as with only 4 GB of RAM you would not be happy with the performance. I would also suggest upgrading to at least the 7200 RPM drive or to a SSD (and also plan on also adding an external drive)

I planed to add ram and ssd after purchase, it's cheaper, and I'll get 16GB of memoryю Also, I heared 2.6 i7 is not significantly faster than 2.3. So, all the improvements in higher-end mbp is not too interesting for me...